Page 43 - BJS Vol 33 & 34

Prevalence of Some Major Insect Pests in Sugarcane Clones 33

Table 4. Infestation levels of some major insect pests in promising BSRI clones
(RSRS, Thakurgaon, 2008-2009).
Percent pest infestation (Mean of three replications)
Clones/
Variety ESB BB TSB SB SB RSB SI MB
(stalk) (internode)
I 7-03 0.45 1.48ab 3.04b 21.71b 9.87 71.78 12.01cd 8.33
I 78-03 0.89 3.65b 17.82a 35.36a 12.64 63.95 47.49b 5.65
I 111-03 0.55 2.83ab 2.36b 15.73b 14.41 63.55 33.73bc 8.13
I 137-03 0.20 1.06a 3.58b 17.55b 17.85 60.34 74.97a 7.62
I 231-03 0.87 2.07ab 1.48b 9.41b 16.75 54.60 23.37cd 6.37
Isd 36 0.52 1.55ab 4.56b 10.71b 10.82 73.65 27.68bcd 7.57
Isd 37 0.57 2.11ab 3.30b 10.47b 14.23 62.04 77.50d 11.45
LSD (5%) 1.146 2.307 3.635 12.34 NS NS 21.87 NS

ESB = Early shoot borer, BB = Black beetle, TSB = Top shoot borer, SB = Stem borer,
RSB = Rootstock borer, SI = Scale insect, MB = Mealy bug, NS = Non significant
* Figures followed by the same letter (s) are not significantly different at 5% level as per LSD test

In the cropping season 2009-2010 no statistically significant difference in
infestation by top shoot borer, stem borer (stalk basis), stem borer (internode basis),
scale insect and mealy bug at Ishurdi and black beetle and top shoot borer at RSRS
Thakurgaon (Table 5 & 6). At both locations early shoot borer infestation was low. Due to
infestation black beetle the lowest infestation (0.70% & 1.52%) was observed in the clone
I 137-03 with the highest of 4.64 and 3.15 percent in I 78-03 at Ishurdi and Thakurgaon
respectively. The clone I 231-03 had the lowest (14.93% & 12.14%) top shoot borer
infestation with the highest (22.05% & 20.67%) in I 78-03. Heavy stem borer infestation
was observed at Ishurdi. The lowest stem borer (stalk basis) infestation was 60.55
percent in I 231-03 at Ishurdi and 19.51 percent in I 231-03 at Thakurgaon. Stem borer
infestation on internode basis showed the lowest (24.29% & 10.18%) in the clone I 7-03.
Heavy rootstock borer infestation was found at both locations. At Ishurdi, infestation
ranged from 41.54 to 62.75 percent and 71.94 to 90.49 percent at Thakurgaon. Scale
insect infestation varied from 4.60 to 14.74 and 13.59 to 54.94 at Ishurdi and Thakurgaon
respectively. Mealy bug infestation varied from 13.46 to 18.81 at Ishurdi with the highest
(18.81% & 71.85%) in standard in Isd 37. Monowara et al. (2011) reported that clones
viz.,I 111-03, ,I 145-02, I 191-02 and standard variety Isd 16 and Isd Isd 36 showed 0.67
to 2.22 % infestation by early shoot borer, 0.70- 3.33% by black beetle. They also
reported 21.05 to 29.77% percent infestation by top shoot borer , 19.35 to 35.89% (stalk
basis) infestation by stem borer, 18.40 to 56.43% infestation scale insect. The test
clones and standard varieties in the present study exhibit more or less similiar results as
was reported.